Die head



1927' w. A. LEONARD DIE HEAD 2 Shets-$heet 1 Filed Nov. 25. 1921 Feb. 15,1927.

W. A LEONARD DIE HEAD Filed Nov. 25 1921 2 Sheets-Sheet 2 Patented Feb. 15, 1927.

UNITED STATES P Al'ENT OFFICE.

VJILBUR A. LEONARD, F MILFORD, CDN'NECTZGUT, ASSIGNOR TO THE GEOMETRIG TOOL COMPANY, OF NEW HAVEN, CONNECTICUT, A GORIPORA'JIION.

DIE HEAD.

Application filed November 25, 1921.

My invention relates to die heads and more particularly to an automatically opening die head, which may, by cooperation with a suitable stop or the like, be arranged to open at a predetermined time in its operation regardless of the direction in which the head may be rotating. Moreover, die heads of this character are usually of a complex nature and are, therefore, more or less 6X- pensive to manufacture and to maintain in operation. I have contemplated the construction of a serviceable and efficient device of this character, which is relatively simple in construction, and which may be manufactured at a relatively low cost.

While certain novel features of my improvements may be particularly adapted to a die head which opens automatically or otherwise to permit the withdrawal thereof from the work, it will be obvious as the description proceeds that my invention is not limited to a device of this character, but in many of its aspects is applicable to die heads of other kinds.

One object of my invention is the provi sion of a die head of simple and economical construction which shall be provided with mechanism to permit the dies to open or separate at a predetermined time regardless of the direction in which the die head may be rotating.

Another object of my invention is to provide a die head with means for mounting the dies therein, such that the face of the die head may be brought into close proximity with the work holder or any object which might intervene to limit the range of relative movement between the die holder and the work.

Another object of my invention is to provide a die holder of such construction that the dies may be easily removed therefrom and replaced with others when desired.

A still further object of my invention is to provide a die head which may be economically and cheaply constructed and which shall at the same time possess all the advantages and functions common to devices of this character.

To these and other ends the invention consists in the novel features and combinations of parts to be hereinafter described and claimed. I

In the accompanying drawings: 7

Serial No. 517,680.

Fig. 1 is a side elevational view of a lathe and support shown more or less conventionally with my improved die head mounted in operative position;

Fig. 2 is a front elevational view of a die head embodying my improvements.

Fig. 3 is a sectional view on line 3-3 of Fig. 2;

Fig. 4: is a sectional view on line 1-4: of Fig. 3;

Fig. 5 is a sectional View on line 55 of Fig. 4:;

Fig. 6 is a sectional view on line 66 of Fig. 5;

Fig. 7 is a view similar to Fig. 3, partly in section and showing the die head in its open position;

Fig. 8 is a side elevational view of my die head with the parts separated to show the construction thereof and to illustrate the position assumed by them when the removal of the dies from the die stock is permitted;

Fig. 9 is a sectional .view similar to Fig. 5, but showing the die head in opened position; and

Fig. 10 is a detail plan view of the controlling plunger.

With refer-ence to the particular construction illustrated in Fig. 1 of the drawings, I have shown at 10 a lathe bed having mounted thereon a pair of brackets 11 provided with hearings to support a head stock 12 provided with the usual cone or stepped pulley 13 and a work holder 14: in which may be mounted a suitable work piece in the form of a rod 15 designed to be threaded. Upon the opposite end of the bed 10 may be provided a tool holder in the form of a turret 16 upon which is mounted my improved die head 17. The turret l6, conventionally shown in 1, illustrates one way in which the diehead 17 may be mounted, it being understood that the turret is of suitable construction interior-1y, that rotation of the die head may be effected, though aside from the fact that such motion is desirable and that the die head is preferably used with such a type of turret, construction of the turret forms no part of this invention. Under some conditions, the die head would be mounted upon the head stock or the equivalent part of a different type of machine in place of the work holder 14, while the work would be supported in a reciprocable carriage equivalent to the turret construction 16. The invention, therefore, is not intended to be limited by the specific machine structure shown in Fig. 1, except in that the conventional showing of Fig. 1 includes a work support and a tool support, capable of relative movement toward and away one from the other, and in which a stop member is aflixed to one in position to act upon the other at a certain period in the operation of the machine.

The die head consists generally of a die stock 18 generally cylindrical in shape and provided with a hollow shank l9, and a cup shaped member 20, the side wall of which forms a ring or collar 21 embracing the die stock and which is provided with a .bevelled camming surface 22 for a purpose hereinafter described. The bottom 22-) of this cupshaped member is provided with an opening 2% through which the shank of the die stock passes.

The die stock 18 is provided with a plurality of radially formed slots 25 provided with keys 26 projecting transversely from one wall thereof. In these slots are slidably mounted the dies or die members 27 which are provided with keyways 28 to receive the keys 26. In this way the dies are mounted in the stock for sliding radial movement relatively to the axis of the tool. In order that the dies 27 may be normally urged outwardly to a predetermined position, each is provided with a small rearwardly projecting pin 29 which engages the head 30 of a plunger 31 mounted in a recess 32 immediately to the rear of the die slot 25 and in which is also mounted a spiral spring to urge the plunger away from the axis of the tool. In order to prevent the plunger 31 from being completely expelled from the die stock by the spring 33, a screw or the like 34 may be mounted in the stock adjacent the plunger and provided with an enlarged head 85 which projects into the recess 32 and engages the head 30 of the plunger when the latter is urged outwardly by the spring 33. It will be obvious that the dies while urged to their open position by the spring will not be permitted to be completely expelled from the stock due to the overlapping edge of the cup shaped member 20 and that the plunger 31 is retained in operative position at all times due to the screw head 35 as shown in Figs. 7 and 8.

Referring more particularly to 8, it will be seen that the rear faces or edges of the die members are bevelled or canrshaped, as shown at 36, and normally project outwardly beyond the periphery of the die stock 18. hen the cupshapcd member 20 is moved to the left in this figure until it assumes the position shown in Figs. 3 and 5, it will be apparent that the bevelled cam surface 22 will cooperate with the edge 36 of the die members to urge them inwardly to their operative or cutting position within the recess 37 formed in the face of the die stock. This cup-shaped member is retained in position to close the dies, as shown in Fig. 5 by the cooperation of a movable member or plunger 38 and pin 39 having a head 40, which is permitted to pass through an opening ell in the plunger and to thereafter he engaged at the shoulder formed by the head 40 by the edge about the opening ll in the movable member 38 to prevent a reverse movement.

The plunger is mounted in a iecess 42 in the bottom 23 of the cup-shapedmember and is provided with a pair of laterally ex tending wings 43 with which engage a pair of spring-pressed pins to normally urge the plunger outwardly in position to engage the head of the pin 39. To limit the sliding or reciprocal movement of the plunger within the recess L2, the former is provided with a slot 45 through which is passed a pin l6. It will be apparent that while the plunger will be permitted a limited amount of movement, it will be prevented from being expelled from its seat by the pin it The opening 41 in the plunger is bevelled, as at 47, upon the side facing the pin 39, so that although the plunger may be at its outer position, it will be camnied inwardly by the engagement of this part of the opening with the head 40 of the pin to permit the passage of the pin therethrough. A pair of spiral springs 48 are mounted in recesses if) in the die stock and bear against the inner surfare of the bottom 23 of the cup-shaped member to nornially urge this member away from the die stock or to the right, as shown in Figs. 3, 5 and 7.

To ordinarily limit the relative movement between the cup shaped member and the die stock, a pin 50 is mounted in the cup shaped member 20 and urged inwardly into engagement with a slot in the shank 19 by a spring 52 surromiding the pin 50 and reacting against a plug 53 in the opening in which the pin is mounted and the enlarged pin head 54-. it will be apparent that when it is necessary or desirable to change the dies, the end of the pin 50, which is mounted in arecess 55 for this purpose, may be grasped by the fingers and pulled outwardly, thus removing its head 5st from en agement with the slot 51 and ])lillitilllf,1' the cup-shaped member 20 to be completely withdrawn from the die stock, so that access may be ob ained to the die members which may then be freely removed from the re cesses 25 in which they are mounted.

In order to cover the recess 42, which 1' find it convenient to form from the outside surface of the member 23, I provide a plate or the like 56, which may be secured upon the member 23 by any suitable securing I iii) means such as screws or the like 57. This plate is provided with an opening 58 for the reception of the head of the pin 39. A guide pin is secured to the cup-shaped member 20 and is adapted to cooperate with an opening 61 formed in the die stock to guide these two members in their relative movements.

I have provided a simple and convenient means of adjusting the die opening so that the threads may be cut to any predetermined depth upon asuitable piece of stock. It will be apparent that the farther the ring 21 with its bevelled surface 22 is drawn to the left, the greater will be the camming action upon the edges 36 upon the die members and hence the smaller the die opening. Ordinarily this ring or collar 21 will be held in a predetermined position relative to the die stock by means of the engagement of the underface of the pin head 40 with the outer face of the plunger 38. In the form shown. I have formed the pin 39 upon a threaded screw 62 mounted in the face of the die stock. It will be apparent that when the screw 62 is rotated. it will draw the ring 21 closer to the face of the die stock, or if rotated in the opposite direction permit it to be moved farther therefrom by means of the springs 48. That is to say by turning the threaded screw 62 I may by means of the beveled surface 22 cam the die members closer together to reduce the die opening, or by permitting the ring 21 to be moved to the right, as shown in Fig. 5, the die opening may be enlarged so that a shallower thread may be cut. The face of the die stock may be provided with rulings 63 to inclicate the amount the die opening is adjusted, by the rotation of the screw. As shown, each of the marks or rulings 63 denotes a change of .001 of an inch.

To provide for the automatic opening of the die head, the plunger 38 is provided with cam-shaped surfaces upon each side thereof. These cam-shaped surfaces are adapted to cooperate with a suitable stop or the like 66 which is shown in Fig. 1 as being mount ed upon the frame of the machine. It will be apparent that when the stop 66 is reached the plunger 38 protruding as it does from the rotating die head will be moved inwardly thereby against the tension of the springpressed pins 44 and the pin head 40 will be disengaged from the ed ge of the opening 41. The springs 48 will then move the cupshaped member to the right to the position shown in Figs. 7 and 9 and the die members will be moved outwardly by the springs to open the die. The opening 41 may be somewhat irregular in shape so as to permit the passage therethrough of the head 40 of the pin 39 on one position thereof and yetprovide for an engagement of as much of removed and replaced at will.

the edge of the opening as is possible with the head in the other position.

The operation of my device is as follows: With the parts in the position shown in Fig. 8,it will be apparent that the dies 27 may be When the proper dies are in position, the cup-shaped member 20 is moved toward the left after the pin 60 has been aligned with the opening 61 until the pin 39 passes through the plunger 38. The lunger will then spring to its outward position under impulse of the pins 44 so that theinner edge of the opening 41 will engage below the head 49 of the pin. During this movement the head 54 of the pin 50 will spring into the slot 51. The cupshaped member 29 will now be more or less rigidly connected to the die stock so that the dies willfbe held securely in pr per position by the bevelled surface 22. If it is desired to vary the size of the die opening, the screw 62 is rotated the proper amount and thus produces a relative movement between the bevelled surface 22 and the edges 36 of the dies. When a predetermined point in the cutting operation has been reached, either of the cam surfaces 65 may come in contact with the stop 66 and the plunger 38 pressed inwardly thereby. The edge of the opening 41 is thereby disengaged from the head 40 of the pin and the springs 48 move the cupshaped member to the right to a position,

shown in Figs. 7 and 9, the movement being limited by the engagement of the pin 50 in the slot 51. The opening of the die is thus automatically accomplished and the work may now be moved longitudinally from the die opening without the necessity of the rotation thereof. After the removal of the work from the opening in the die, either by the movement of the die away from the work or vice versa, a blank piece of work is substituted in the work holder for the completed one. Meanwhile, the member 20 has again been moved to the left to cause the dies to assume their operative closed ositions as shown in Fig. '4', either by hand or other suitable means, and the operation of threading this new piece is started.

If it is desired to change the dies, it is only necessary to grasp the end of the pin 50 and pull this pin outwardly to disengage the head thereof from the slot 51 and the cup-shaped member 20 may be moved to the position shown in Fi 8 to permit the dies to be freely removed from the slots in which they are located.

It will be apparent that with the provision of the cooperating keys 26 and keyways 23 a very smooth and even movement of the dies is accomplished by the bevelled surface 22. Moreover, when the cup-shaped member 20 is moved to the right to the posi tion shown in Figs. 7 and 9, the dies will be at once automatically moved outwardly by means of the plungers 31.

The operator may, of course, depress the plunger 38 manually at any time desired so as to cause the jaws of the die to open without waiting for the automatic operation by means of the stop 6. Or if no stop is provided, this plunger may be operated entirely by hand.

lVhile I have shown and described a preferred embodiment of my invention, it will be understood that the same is not to be limited thereby in all of its details, butis capable of many modifications and variations which lie within the spirit of the invention and within the scope of the appended claims. I do not limit myself to a die head for thread cutting tools, as it will be obvious that my die stock may be used as a tool holder for surface turning or similar tools. as well as for the particular type illustrated in the drawings.

\Vhat I claim is:

1. In a die head, a die stock, dies movably mounted therein and normally urged to an outward or expanded position, movably mounted means to hold said dies in operative closed position, means engaging said stock and said holding means to positively retain said holding means in operative position, said retaining means being releasa le to permit the moving of said holding means to a position whereby the dies arepermitted to open, and means mounted in said holding means and engaging said stock to limit the movement of said holding means in the die opening direction, said last named means being releasable from engagement with one of said engaged parts to allow further movement of said holding means in the same direction.

2. In a die head, a die stock, dies movably mounted therein, and normally urged to outward or expanded position, movably mounted means to hold said dies in operative closed position, means to rel-ease said holding means to move the same to a posi tion to permit opening of the dies and means carried by said holding means and engageable with said stock to limit the movement of said holding means, said limitln" means being disengageable to permitfurthei mov ment of said holding means in the die opening direction.

3. In a die head, a die stock, dies n'iovably mounted there n, a movably mounted camniing collar to hold said dies in operative position, and means to i leasably secure said collar member in such holding position upon the die stock member, said means comprising a spring pressed plunger upon one of said members provided with an opening and a.

pin upon the other member adapted to pass throu h the o aenln and be engaged by the ti 1: p o .1 edges thereof.

4'. In a die head, a die stock, dies movably mounted therein, a cup shaped member adapted to embrace said stock and to hold the dies in operative closed position, a pin upon the die stock and a plunger mounted in the cup shaped member to engage the pin and prevent relative movement of the members.

5. In a die head, a die stock, dies movably mounted therein, a cup-shaped member adapted to embrace said stock and to hold the dies in operative closed position, a headed pin upon the die stock, a plunger mounted in the cu 'nshaped member and provided with an opening to receive and retain said pin to hold said members against movement.

(3. In a die head, a die stock, dies movably mounted therein, a cup shaped member adapted to embrace said stock and to hold the dies in operative closed position, a headed pin upon the die stock, a plunger mounted in the cup-shaped member and provided with an opening to receive and retain said pin to hold said members against movement, and means to vary the effective length of the pin to vary the cut of the dies.

7. A die head comprising a cylindrical die stock, having a plurality of slidable dies radially mount-ed therein, means to normally urge said dies outwardly to present an end of each beyond the periphery of said die stock, a collar longitudinally slidable upon said die stock, having cam surfaces arranged to act directly against the outwardly extending ends of said dies to move the dies inwardly into operative position when said collar is moved in one direction, and to re ease said dies when moved in the opposite direc-- tion, and adjustable means to adjust the longitudinal relation between said stock and said collar whereby the closed position of said dies is varied, said adjusting means releasably locking said collar against movement in the die releasing direction when said collar has reached the die closing position.

8. A tool holder comprising a cylindrical tool stock, having a plin'ality o't' slidable cutting tools radially mounted therein, said cutting tools being substantially in the form of a square prism with the inner ends there of presenting cutting edges, means to normally urge said tools outwardly to present an end of each beyond the. periphery said tool stock, a collar longitudinally slidable upon said tool stock having cam surfaces arranged to act di ectly against the outwardly extendingends of tfltlil tcols to move the tools inwardly into operative position when said collar is moved in one direction. and to release said tools when moved in the opposite direction, and means to adjust the longitudinal relation between said stock and said collar whereby the closed position of said tools is varied, said adjusting means lit) releasahly locking said collar against move ment in the tool releasing direction when said collar is moved a predetermined amount in the tool closing direction.

9. In a die head, a eylimlrical die stock comprising a rearwardly directed hollow shank portion and a head portion, said heat portion having a plura ity of radial grooves in the front face thereof, and a plurality of openings rearwardly adjacent the grooves in the eriphery thereof, a plurality of dies slidably mounted in the grooves of raid head portion and protruding from the face thereof, each of said dies normally extending without the periphery of said head portion and having a rearwardly directed pin extending into the adjacent opening, spring pressed plungers in each of the openings in the periphery of said head portion adapted to urge said dies outwardly, and a cup-shaped member slidably mounted upon said shank portion and adapted to enclose said head portion and engage the extending portion of said dies to force the same downwardly against the action of the spring pressed plungers.

10. In a die head, a die stock having a radially disposed opening in the end face thereof, a die in the opening of said stock, said die having a cutting edge upon one of its ends, a cam surface upon the other end, a groove in one of its side faces, and a rearwardly extending part upon its rear face, means longitudinally slidable in relation to said stock to engage said cam surface to radially move said die within the opening in said stock, means associated with said stock and engaging said. die within the groove therein to prevent the longitudinal removal of said die from the opening in said stock, and means associated with said. stock and engaging said rearwardly extending portion of said die to urge said die radially outward toward the periphery of said stock.

11. In a die head, a die stock having a radially disposed opening in an end face thereof, a die in the opening in said stock and extending beyond the end face of said stock, means associated with said die and said stock extending from end to end of said die and engaged with said stock within the radially disposed opening in said stool: to prevent the removal of said die longitudinally from said stock, means associated with said stock and engaging said die to urge the same radially outward toward the periphery of said stock, and means longitudinally slid able in one direction on said stock to allow the radially outward movement of said die, said means being movable in another direction to prevent the radially outward movement of said die.

12. In a tool holder, a tool stock having a radially disposed opening therein, a tool substantially square prism in form slidably mounted in the opening in said stock, said tool having a cutting edge formed upon one end, a rearwardly and inwardly directed cam surface upon the other end, means to engage said stock within the radially disposed opening therein extending fr m end to end on one of its surfaces, and a rearwar-dly extending portion intermediate its ends on its rear face, and means to engage said extending portion to urge said tool toward the periphery of said stock and means axially slidable with respect to said stool: engageable with said cam surface to move said tool inwardly against said urging means.

13, In a die head, a cylindrical die stock having radial recesses in the front face thereof and radial openings extending into the periphery of said stock, said recesses and openings intereommunicating, die members in said recesses, a pin extending from each of said die members into each of the openings. means in each of the openings in engagement with each of said pins to urge said die members outwardly, and a collar about the periphery of said stock and slidable thereon into engagement with said die members to move the same inwardly and to retain them in a predetermined position, and means mounted in and operable from the front face of said stock to vary the efiective movement of said collar.

M. In a die head, a die stock, dies movably mounted therein and normally urged to outward or expanded position, a movably mounted collar to hold said dies in operative closed position, a catch to release said collar, a. spring acting against said collar to move the same to a position to permit opening of the dies, and a member carried by said collar and engageable with said stock to limit the movement of said collar, said member being disengageable from said stock to permit further movement of said collar in the die opening direction.

15. A die head comprising a cylindrical die stock having a plurality of slidable dies radially mounted therein, means to normally urge said dies outwardly to present an end of each beyond the periphery of said die stock, a collar longitudinally slidable upon said die stock and adapted to engage the outer ends of said dies to move the same inwardly into operative position when said collar is moved in one direction and to release said dies when moved in the opposite. direction, and means cooperating with said collar and said stock to adjust the longitudinal relation therebetween whereby the closed position of said dies is varied, said adjusting means releasably locking said collar to said stock, when said collar has reached a predetermined die closing position.

16. A die-head comprising a die-stock, dies carried thereby, a locking-abutment also carried by the said die-stock, a die-operating member having a forward or die-closing position and a rearward or die-retracted position, va spring normally urging the said die-operating member rearward, a releasable locking-member tor the said die-open ating member for holding the same in its die-closing position and bodily movable diametrically with respect thereto, and a transverse passage formed in the said locking-li'ielnber for the reception of the said locking-abutm-ent 17. A die-head con-rprising a die-stock dies carried thereby, an adjustable lockingabutment also carried by the said die-stock, a die-operating member having a forward or die-closing position and a. rearward or die-retracted position. a spring normally urging the the said die-operating member rearward a releasable plate-like lockingmember carried by the said die-operating member for holding the same in its die-closing position and bodily mova ble diametrically with respect thereto, and a transverse opening formed in the said plate-like lockmg-member for the reception of the sand adjustable locking-abutment.

18. A die-head comprising a die-stock carrying a plurality of radially-movable dies, an axially-movable die-operating mem her having a die-closing position and a dieretracted position, a spring normally urging the said die-operating member into its die-retracted position, an adjustable locking-abutment carried by one ot the above mentioned members, a releasable lockingmember carried by the other ot the said members and having bodily movement dia metrically with respect thereto and provided with a passage for the reception of said locking-abutment, whereby the die-operating member may be releasably held in its dieclosing position, against the tension of the said spring.

In Witness whereof, I have hereunto set my hand this 21st day of November, 1921.

lVILBUR A. LEONARD. 

